| Popis: |
The role of satellites in medium and high-resolution reconnaissance of the Earth has been well demonstrated in recent years through missions such as Landsat, SPOT, IKONOS, EROS, ImageSat and Quickbird. Medium resolution data products have added significantly to Earth science, but commercial markets have concentrated on enhancing resolution. The markets for such high-resolution data products are well served, and are likely to become more competitive with further planned high-resolution missions. The small satellite sector has concentrated on reducing the cost of specialised data products that are ill served by current missions, and on the development of systems providing niche services. One such area where smaller satellites can provide a distinct advantage is in meeting the needs for higher temporal resolution, as this typically requires multiple satellites to operate as a constellation. Such a system has been discussed widely in the disaster monitoring community, Surrey is currently engaged in launching its first constellation to provide daily global coverage at moderate resolution in three spectral bands, as part of a system to provide global disaster monitoring. The first spacecraft in this Disaster Monitoring Constellation (DMC), ALSAT-1, was launched in late 2002. The programme employs novel models for international collaboration, and demonstrates how small satellite missions can be employed in emerging applications. This paper provides an overview of the DMC programme, details the ALSAT-1 spacecraft and payload, and provides the first in-orbit mission results from ALSAT-1. The paper also addresses the future of the programme, and an update of the second DMC launch due in August 2003. The latest results of the 3rd DMC Consortium meeting will also be reviewed. |
